TW201734332A - Ball screw capable of achieving a maintenance-free lubrication by supplying a lubricant to an oil supply member from an oil-containing member - Google Patents

Abstract

The present invention provides a ball screw suitable for assembling various kinds of equipment such as an electromechanical product, an inspection device and the like, which can supply a lubricant to an oil supply member 6 from an oil-containing member 5, and enable the ball that rolls in a direction change passage 14 to come into touch with the oil supply member 6 for supplying lubricant so as to be free from lubrication maintenance. The ball screw includes a screw shaft 1 with a spiral groove 11 and a nut 2 that moves relative to the screw shaft. The nut 2 includes a nut body 3 formed by a spiral groove 12 and a reflowing passage 13, an end cap 4 installed to the nut body 3 and provided with the direction change passage 14 in communication with a spiral track passage 15 and the reflowing passage 13, the oil-containing member 5 disposed on the end cap 4, and the oil supply member 6 disposed in a communicating hole 20 of the end cap 4.

Description

Ball screw

The present invention relates to a ball screw for use in various machine assemblies such as an electromechanical integrated product such as a platform for determining a precise position, an inspection device, and the like, and has a grease supply mechanism, a screw shaft and a nut that moves relative to the screw shaft. Composition.

A linear motion device that supplies a lubricant in a self-lubricating manner is disclosed in Japanese Laid-Open Patent Publication No. 2013-174255. The linear motion device is a ball screw driving device of the end steering device, and comprises a nut having a spiral groove formed on the inner circumferential surface, a screw shaft formed on the outer circumferential surface and a spiral groove opposite to the spiral groove of the nut, and the screw can be assembled The spiral groove of the cap and the spiral groove of the screw shaft form a plurality of balls between the spiral track faces. The inside of the nut forms a return passage in the axial direction, and the surface is integrally molded by the oleoresin material.

Further, in order to improve the degree of freedom of design, the present applicant has developed a rolling guide unit which is simple in lubricant management and has little sliding resistance to rolling elements, and has been filed (see, for example, JP-A-2006-38195). The rolling guide unit includes a tubular member slidably passed through the rail, a rail passage formed by the combination of the tubular member and the rail, a circulation passage formed by the tubular member forming the both ends of the rail passage via the recess of the steering passage, and the circulation passage And a plurality of rolling elements that roll with the above-mentioned track path. The rolling guide unit circulates the rolling elements in the circulation passage and the track passage in response to the relative movement of the rail and the tubular member. The rolling guide unit includes an assembly hole forming a tubular member, an oil-containing member assembled in the assembly hole, an oil supply member disposed along a contact surface of the rolling body or a rolling element in the circulation passage, and the supply member and the oil-containing member contact.

However, the above-described linear motion device is molded in the nut return passage by injection molding using an oil-containing resin material, and is integrally molded with the nut. The problem of the above oil-containing resin material is that the resin material and the lubricating oil are mixed, and the mixed material is injected and molded. If the lubricating oil has a small capacity, the lubricating oil cannot be supplied, the lubrication is liable to occur, and the nut and the oil must be supplied. The resin material is integrally molded and molded, which is costly and increases the manufacturing cost. In addition, the rolling guide unit has a problem, and an oil supply member is disposed in the steering passage of the end cover of the ball bolt slot, and the outer cylinder is provided with an oil-containing member. In order to achieve lubrication-free maintenance, when the oil-containing member is assembled in the assembly hole, it is not sufficient to supply the lubricating oil from the oil-containing member to the oil supply member.

An object of the present invention is to provide a ball screw, which is suitable for assembling various devices such as an electromechanical integrated product such as a platform for determining a precise position, an inspection device, and the like, and a concave portion is formed on an outer end surface of an end cap constituting the inner reflow plate. The concave portion is configured to saturate the oil-containing member for supplying the lubricating oil, so that the device body can be configured compactly and easily, and the oil supply member is embedded in the communication hole of the opening of the end cover steering passage, and the oil-containing member and the oil supply member are porous with the saturated lubricant. The sintered resin is formed, and the lubricant is often supplied from the oil-containing member to the oil supply member, and the balls of the rolling elements rolling in the turning passage contact the exposed surface of the oil supply member, so that the lubricant is surely supplied to the balls to achieve lubrication-free maintenance. .

The ball screw of the present invention comprises a rotatable screw shaft, and a first spiral groove which is formed in a spiral shape on the outer peripheral surface to be rolled by a plurality of rolling elements; and a cylindrical nut which is formed in the axial direction on the inner circumferential surface a second spiral groove that is slidably engaged with the outer peripheral surface of the screw shaft and opposed to the first spiral groove, and the nut is relatively moved longitudinally above the screw shaft according to the rotation of the screw shaft; The cap includes a cylindrical nut body, forming a return passage, extending in the axial direction of the second spiral groove and the rotation of the ball; and the end cover forming a steering passage respectively disposed at both ends of the nut body, and The first spiral groove and the second spiral groove form a spiral track passage, and the return passage communicates; the oil-containing member is disposed on an outer end surface of the end cover, saturates the lubricant; and an oil supply member is formed at the end a cover, and is disposed in a communication hole communicating with the steering passage and the outer end surface of the end cover on the oil-receiving member side; an end surface of the oil-receiving member side of the oil supply member is integrally provided with an elastic convex portion crimped to the oil-containing member Department The other end surface of the member is supplied to the ball when the ball is rolled in contact with the ball in the steering passage, and the convex portion of the oil supply member is crimped to the oil-containing member, and the lubricant is supplied to the ball. Oil component.

The ball screw of the present case is provided with a cover covering the outer surface of the oil-containing member, and the cover is fixed to the nut body via the end cover and the oil-containing member. Moreover, the nut body has a flange portion A mounting hole is formed for mounting the counterbalancing member.

Further, the oil-containing member is housed in the cover provided on the outer end surface of the end cover, and forms a C-shaped annular shape in accordance with a direction in which the convex portion for sealing is provided in the cover. The ball screw is rotated by the screw shaft, and the ball can roll in a circulating path formed by the spiral track path, the return path and the turning path, and the nut can be relatively moved in the longitudinal direction by the ball on the screw shaft .

Further, the screw shaft has a pivot shaft screw shaft that is rotatably supported at both ends. Further, the communication hole formed in the end cover is opened on the outer wall surface in which the steering passage is curved in an R shape. The other end surface of the oil supply member exposed in the steering passage is formed in the same manner as the R-shaped curved outer wall surface.

Further, the width of the other end surface in which the steering passage of the oil supply member is exposed is set to be substantially in the range of 1/4 to 1/2 of the diameter of the ball. Further, the end cap is an internal return plate, and a convex portion formed by the steering passage communicating with the spiral track passage and the return passage is formed, and a gripper for the ball on the side of the spiral track passage is gripped. The convex portion of the internal reflow plate is engaged with a concave portion that is respectively connected to an end portion of the second spiral groove formed at an end portion of the nut body.

Further, the oil-containing member and the oil-receiving member constitute a porous molded body, and have a porous portion which is made of polyethylene or polypropylene synthetic resin fine particles, which is formed by extrusion thermosetting and maintains communication between the synthetic resin particles. status. The lubricant is saturated with the porous portion of the porous formed body.

The ball screw of the present invention has the above-mentioned configuration, and the device itself is simple and compact, and the oil-containing member disposed in the concave portion of the cover provided on the outer end surface of the end cover is saturated with a large amount of lubricant, and the oil supply member convex portion is disposed when the end cover communication hole is disposed. When pressed to the oil-containing member, the lubricant is smoothly transferred from the oil-containing member to the oil-receiving member by capillary action or the like. The lubricant saturated with the oil-containing member is smoothly supplied to the oil supply member, and the ball rolling in the steering passage is in contact with the exposed end surface of the oil supply member, and the lubricant is easily oozing out from the oil supply member, and the lubricant is supplied to the ball, that is, Lubrication and maintenance of ball screws can be implemented. Further, the rolling screw is disposed in the oil-containing member of the recess of the cover to form a C-shaped ring. Further, a sealing convex portion that is fitted to the spiral groove of the screw shaft is provided on the inner peripheral side of the cap, and the sealing convex portion prevents foreign matter from entering. In addition, the outer side of the oil-containing member is covered with a cover, and no lubricant is scattered to cause deterioration of the surrounding environment.

1‧‧‧ screw shaft

2‧‧‧ nuts

3‧‧‧The nut body

4‧‧‧End cover

5‧‧‧ oil-containing components

6‧‧‧ Oil supply components

7‧‧‧ Cover

8‧‧‧ nut body flange

9‧‧‧ balls

10‧‧‧The outer circumference of the screw shaft

11‧‧‧First spiral groove

12‧‧‧Second spiral groove

13‧‧‧Return path

14‧‧‧Steering path

15‧‧‧ spiral track path

16‧‧‧Circular access

17‧‧‧The inner surface of the nut body

18‧‧‧The end of the nut body

19‧‧‧End face of the end cap

20‧‧‧End cover communication hole

21‧‧‧ oil bearing end face

22‧‧‧ oil bearing end face

23‧‧‧ oil supply member convex

24‧‧‧ outside the oil-containing components

25‧‧‧Installation holes

26‧‧‧ Screw shaft end

27‧‧‧Outer side wall

28‧‧‧ Nut body recess

29‧‧‧ gripper

30‧‧‧End cap projections

31‧‧‧ fixing screws

32‧‧‧Gap section

33‧‧‧ nut body jack

34‧‧‧End cover jack

35‧‧‧ Oily component jack

36‧‧‧ oily component recess

37‧‧‧ Cover jack

38‧‧‧ Cover end

39‧‧‧Circular outer circumference

40‧‧‧ Cover recess

41‧‧‧ countersunk mounting holes

42‧‧‧End cap end face

43‧‧‧End cover mounting holes

44‧‧‧ openings

45‧‧‧Inside end face of oil-containing component

46‧‧‧ Nut body mounting screw hole

47‧‧‧ nut body end face

50‧‧‧ Sealing convex

1 is a perspective view showing an embodiment of a ball screw of the present invention; FIG. 2 is an exploded perspective view showing a nut constituting the ball screw of FIG. 1; and FIG. 3 is a partial cross-sectional view showing the ball screw of FIG. a partial side view of the circulation passage; Fig. 4 is a front view showing the outer end surface of the end cap constituting the ball screw of Fig. 3; Fig. 5 is a sectional view showing the position of the end cover AA constituting the ball screw of Fig. 4; Fig. 4 is a rear view of the inner end surface of the end cap; Fig. 7 is a view showing the oil supply member constituting the ball screw of Fig. 1, (A) is a side view, (B) is a plan view; and Fig. 8 is a view showing a ball screw constituting Fig. 1 Oil-containing member, (A) is a front view, (B) is a side view; Figure 9 is a cover constituting the ball screw of Fig. 1, (A) shows a front view of the outer end face, and (B) shows a position of the BB position of (A) A cross-sectional view, (C) shows a rear view of the inner end face, and (D) shows a side view.

The ball screw of the present invention is preferably applied to various machines such as an electromechanical integrated product such as a platform for determining a precise position, an inspection device, and the like.

An embodiment of the ball screw of the present invention will now be described with reference to the accompanying drawings. As shown in Figs. 1-3, the ball screw of the present invention includes a screw shaft 1, which is a rotatable ball screw shaft, and a spiral groove 11 (first spiral groove) is formed on the outer peripheral surface 10 thereof in the axial direction for re-rolling. The ball rolling of the body; and the cylindrical nut 2 are fitted over the outer peripheral surface 10 of the screw shaft 1, and a spiral groove 12 (second spiral groove) is formed in the inner circumferential surface 17 thereof in the axial direction, opposite to the spiral groove 11 The balls 9 are caused to roll, and the nut 2 is relatively moved in the longitudinal direction on the screw shaft 1 in response to the rotation of the screw shaft 1.

Specifically, the nut 2 is characterized in that it comprises a cylindrical nut body 3, a spiral groove 12 is formed, and a return passage 13 of the ball 9 extending in the longitudinal direction of the rolling; the end cover 4 forms a spiral track passage 15, respectively It is disposed on both end faces 47 of the nut body 3, and is formed by the spiral groove 11 and the spiral groove 12, and the steering passage 14 communicates with the return passage 13; the oil-containing member 5 is disposed at the outer end surface 19 of the end cover 4, and is saturated. The lubricant member 6 and the oil supply member 6 are disposed with the communication hole 20, and are formed in the end cover 4, and communicate with the steering passage 14 and the outer end surface 19 of the end cover 4 on the oil-containing member 5 side. The ball screw is provided with a cover 7 on the nut 2 to cover the outer surface 24 of the oil-containing member 5. Cover 7 The nut body 3 is fixed to the nut body 3 by the fixing screws 31 via the end cover 4 and the oil-containing member 5. The nut body 3 has a plurality of mounting screw holes 46 formed in the end surface 47 thereof. The fixing screw 31 is inserted through the countersunk mounting hole 41, the recess 36 of the oil-containing member 5, and the mounting hole 43 of the end cover 4, and is screwed into the mounting screw hole 46 of the nut body 3, and the end cap 4, the oil-containing member 5 and the cover are attached. 7, fixed to the nut body 3.

The ball screw is inserted into the nut 2 with the screw shaft 1, and since the screw shaft 1 is to be inserted into the nut 2, the nut body 3 constituting the nut 2 is formed with the insertion hole 33, the end cover 4 is formed with the insertion hole 34, and the oil-containing member 5 is formed. The jack 35 and the cover 7 form the jacks 37 which are respectively aligned. Further, the oil-containing member 5 is housed in the lid 7 disposed on the outer end surface 19 of the end cap 4, and is formed in a C-shaped annular portion notch portion 32 by being fitted in the direction of the sealing convex portion 50 provided in the lid 7. The sealing convex portion 50 is provided to engage with the spiral groove 11 of the screw shaft 1, and since the gap between the screw shaft 1 and the nut 2 is small, the sealing convex portion 50 has a function of a labyrinth seal, thereby preventing entry of foreign matter. When the cover 7 and the oil-containing member 5 are assembled, the sealing convex portion 50 of the cover 7 and the notch portion 32 of the oil-containing member 5 are fitted together. The oil-containing member 5 has a concave portion 36 formed on the outer peripheral surface thereof for the insertion of the fixing screw 31. The center of the cover 7 forms an insertion hole 37 of the plug-in screw shaft 1, and an outer surface 38 that covers the oil-containing member 5 is provided on the outer side, and an annular outer peripheral surface 39 is formed around the outer peripheral surface 39, and a recess 40 for accommodating the oil-containing member 5 is formed inside the outer peripheral surface 39. Further, the cover 7 is provided with a plurality of (four shown in FIG. 9) countersunk mounting holes 41 for the insertion of the fixing screws 31. The oil-containing member 5 is housed in the recess 40 of the cover 7, and is assembled in an outer cover state.

The screw shaft 1 is formed at both end portions 26 to constitute a rotatably supported round shaft type ball screw shaft. Further, the nut body 3 is a pair of opposing members such as a mounting member, a tool, and a machine, and the flange portion 8 on which the mounting hole 25 is formed is provided at one end portion 18. The end cover 4 is formed in a convex portion 30 of an internal return plate, forming a gripper 29 for grasping the ball 9 which is rolled by the spiral groove 11 on the side of the screw shaft 1; a turning passage 14 for turning the ball; and a port portion, There is an inlet and outlet for guiding the ball 9 from the steering passage 14 to the return passage 13. The convex portion 30 of the end cap 4 can be inserted into the nut body 3 to form a recess 28 as a sleeve hole at the both end portions 18, a turning passage 14 formed in the end cover 4, and a spiral groove 12 formed by the nut body 3. The same.

The circulation passage 16 of the ball 9 of the ball screw includes a spiral track passage 15 which is constituted by the ball 9 in the spiral groove 11 of the screw shaft 1 and the spiral groove 12 of the nut body 3; the return passage 13 formed by the nut body 3 And a steering passage 14 formed in a pair of end caps 4, respectively. This ball screw generally rotates the ball shaft 1 in response to the rotation of the screw shaft 1, and the nut 2 is relatively moved in the longitudinal direction by the ball 9 on the screw shaft 1.

The ball screw feeds the lubricant from the oil-containing member 5 disposed outside the end cover 4 to the steering passage 14 via the oil supply member 6, and supplies it to the balls 9. The oil-impregnated member 5 is disposed on the outer end surface 19 of the opposite side of the end surface 42 where the end portion 4 is formed with the convex portion 30 (second drawing). The communication hole 20 formed in the end cover 4 has one end bent in the R shape in the steering passage 14, the rectangular opening portion 44 of the outer side wall surface 27 is opened, and the other end is opened at the outer end surface 19 of the end cover 4. The communication hole 20 formed by the end cover 4 is inserted into the end surface 21 of the oil supply member 6 of the steering passage 14 and is formed in the same shape as the outer side wall surface 27 of the steering passage 14 to form the same R-shaped curved shape. In particular, the end surface 22 of the oil supply member 6 on the oil-containing member 5 side is provided with a lubricant, and is integrally provided with an elastically deformable portion 23 which is elastically deformed by the inner end surface 45 of the oil-containing member 5. In the case of the ball screw winter, the convex portion 23 at one end of the oil supply member 6 is placed in contact with the end surface 45 on the end cover 4 side of the oil containing member 5, so that it is screwed into the mounting screw hole 46 of the nut body 3 by the fixing screw 31, that is, The convex portion 23 can be formed in a crimped state, and the oil supply member 6, the oil-containing member 5, and the lid 7 of the end cover 4 are fixed to the nut body 3. Since the convex portion 23 of the oil supply member 6 is attached to the end surface 45 of the oil-containing member 5 and is in a pressure-bonded state, the oil-containing member 5 is saturated with the lubricant, and can be smoothly moved to the oil supply member 6, and the oil-containing member 5 is saturated with the lubricant. That is, it is smoothly supplied to the oil supply member 6. Further, one end surface 21 of the oil supply member 6 is in contact with the ball 9 rolling in the steering passage 14, and the lubricant is supplied to the ball 9, and the other end surface 22 of the oil supply member 6 is formed to be in pressure contact with the oil-containing member 5, and the lubricant That is, it is supplied to the oil supply member 6. Further, the oil supply member 6 has a flat plate shape, and forms an R-shaped circular arc surface extending substantially in the longitudinal direction on the end surface 21 where the steering passage 14 is exposed, and the end surface 21 of the oil supply member 6 has a width which is set to be substantially the diameter of the ball 9 In the range of 1/4 to 1/2, a lubricant can be supplied from the oil supply member 6 to the balls 9.

The oil-containing member 5 and the oil supply member 6 are made of polyethylene or polypropylene synthetic resin fine particles, and are subjected to thermosetting molding to form a porous molded body having a porous portion and maintaining a state of communication between the synthetic resin fine particles. The porous portion of the molded body is saturated with the lubricant. Therefore, the ball screw of the present invention is exposed to the steering passage 14 by the oil supply member 6, and the ball 9 rolling in the steering passage 14 is saturated with the lubrication of the oil-containing member 5 and the oil supply member 6 when it comes into contact with the end surface 21 of the oil supply member 6. The agent, that is, supplied to the ball 9, achieves lubrication-free maintenance. Further, regarding the ball screw of the present invention, the ball screw specification can be, for example, the shaft diameter of the screw shaft 1. 15. The spiral groove 11 formed by the outer peripheral surface 10 of the screw shaft 1 is in a row, and the lead is formed to be 30 mm.

1‧‧‧ screw shaft

2‧‧‧ nuts

3‧‧‧The nut body

4‧‧‧End cover

5‧‧‧ oil-containing components

6‧‧‧ Oil supply components

7‧‧‧ Cover

8‧‧‧ nut body flange

9‧‧‧ balls

10‧‧‧The outer circumference of the screw shaft

11‧‧‧First spiral groove

12‧‧‧Second spiral groove

13‧‧‧Return path

14‧‧‧Steering path

15‧‧‧ spiral track path

16‧‧‧Circular access

17‧‧‧The inner surface of the nut body

18‧‧‧The end of the nut body

19‧‧‧End face of the end cap

25‧‧‧Installation holes

28‧‧‧ Nut body recess

30‧‧‧End cap projections

38‧‧‧ Cover end

Claims (10)

A ball screw comprising a rotatable screw shaft, a first spiral groove which is formed in a spiral shape on the outer peripheral surface to be rolled by a plurality of rolling elements; and a cylindrical nut which is formed on the inner circumferential surface in the axial direction a rolling second spiral groove is fitted to the outer circumferential surface of the screw shaft and opposite to the first spiral groove, and the nut is relatively moved longitudinally above the screw shaft according to the rotation of the screw shaft; the nut The tubular nut body is formed to form a return passage, and the second spiral groove and the axial direction of the ball rotate; the end cover forms a steering passage, which are respectively disposed at both ends of the nut body, and a first spiral groove and the second spiral groove form a spiral track passage, and the return passage communicates; an oil-containing member disposed on an outer end surface of the end cover to saturate the lubricant; and an oil supply member formed on the end cover And a communication hole that communicates with the steering passage and the outer end surface of the end cover on the oil-receiving member side; one end surface of the oil-receiving member on the oil-receiving member is integrally provided with an elastic convex portion that is crimped to the oil-containing member The oil supply The other end surface of the member is supplied to the ball when the ball is rolled in the steering path, and the convex portion of the oil supply member is crimped to the oil-containing member, and the lubricant is supplied to the ball. Oil component. The ball screw of claim 1, wherein the nut is provided with a cover covering the outer surface of the oil-containing member, and the cover is fixed to the nut body by the end cover and the oil-containing member. The ball screw according to claim 1, wherein the oil-containing member is housed in the cover in which the end cover is disposed on the outer end surface, and is fitted in a direction of a convex portion provided in the cover to form a C-shaped ring. The ball screw of claim 1, wherein the nut body has a flange portion to form a mounting hole for mounting the opposing member. The ball screw of claim 1, wherein the ball rolls in a spiral path formed by the spiral track passage, the return passage and the steering passage, and the nut is borrowed on the screw shaft The ball is relatively moved in the longitudinal direction. The ball screw of claim 1, wherein both ends of the screw shaft are formed by a rotatably supported round shaft type ball screw shaft. The ball screw of claim 1, wherein the communication hole formed by the end cover is open on an R-shaped curved outer wall surface of the steering passage, and the oil supply is exposed in the steering passage. The other end surface of the member is formed in the same manner as the R-shaped curved outer wall surface. The ball screw of claim 1, wherein the width of the other end face exposed by the steering passage of the oil supply member is set to a range of substantially 1/4 to 1/2 of the rolling diameter. The ball screw of claim 1, wherein the end cap is an internal return plate, and the spiral track passage and the return passage communicate with each other to form a convex portion of the circulation passage, and the ball that can grip the side of the spiral track passage The gripper is configured such that the convex portion of the internal recirculating plate and the concave portion of the end of the second spiral groove respectively formed at the end portion of the nut body are respectively engaged with the concave portion. The ball screw according to claim 1, wherein the oil-containing member and the oil-receiving member are formed by extrusion molding of polyethylene and polypropylene synthetic resin particles to form a porous molded body having a porous portion to maintain the synthesis. The state of communication between the resin fine particles is obtained by saturating the porous portion in the porous portion.